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Highlights • Proton pelvic reirradiation results in lower bone marrow dose compared to photons. • Proton pelvic reirradiation of the pelvis is well tolerated with limited toxicities., Introduction Pelvic reirradiation (re-RT) presents challenges due to concerns for late toxicity to tissues-at-risk including pelvic bone marrow (PBM). We routinely utilize a hyperfractionated, accelerated re-RT for recurrent rectal or anal cancer in the setting of prior radiation. We hypothesized that proton beam radiation (PBR) is uniquely suited to limit doses to pelvic non-target tissues better than photon-based approaches. Materials and methods All patients who received hyperfractionated, accelerated PBR re-RT to the pelvis from 2007 to 2017 were identified. Re-RT was delivered twice daily with a 6 h minimum interfraction interval at 1.5 Gray Relative Biological Effectiveness (Gy(RBE)) per fraction to a total dose of 39–45 Gy(RBE). Concurrent chemotherapy was given to all patients. Comparison photon plans were generated for dosimetric analysis. Dosimetric parameters compared using a matched-pair analysis and the Wilcoxon signed-rank test. Survival analysis was performed Kaplan Meier curves. Results Fifteen patients were identified, with a median prior pelvic RT dose of 50.4 Gy (range 25–80 Gy). Median time between the initial RT and PBRT re-RT was 4.7 years (range 1.0–36.1 years). In comparison to corresponding photon re-RT plans, PBR re-RT plans had lower mean PBM dose, and lower volume of PBM getting 5 Gy, 10 Gy, 20 Gy, and 30 Gy (p

Purpose Ablative radiation therapy is increasingly being used for hepatocellular carcinoma (HCC) resulting in excellent local control rates; however, patients without evidence of disease progression often die from liver failure. The clinical benefit of proton- over photon-based radiation therapy is unclear. We therefore sought to compare clinical outcomes of proton versus photon ablative radiation therapy in patients with unresectable HCC. Methods and Materials This is a single-institution retrospective study of patients treated during 2008 to 2017 with nonmetastatic, unresectable HCC not previously treated with liver-directed radiation therapy and who did not receive further liver-directed radiation therapy within 12 months after completion of index treatment. The primary outcome, overall survival (OS), was assessed using Cox regression. Secondary endpoints included incidence of non–classic radiation-induced liver disease (defined as increase in baseline Child-Pugh score by ≥2 points at 3 months posttreatment), assessed using logistic regression, and locoregional recurrence, assessed using Fine-Gray regression for competing risks. All outcomes were measured from radiation start date. Results The median follow-up was 14 months. Of 133 patients with median age 68 years and 75% male, 49 (37%) were treated with proton radiation therapy. Proton radiation therapy was associated with improved OS (adjusted hazard ratio, 0.47; P = .008; 95% confidence interval [CI], 0.27-0.82). The median OS for proton and photon patients was 31 and 14 months, respectively, and the 24-month OS for proton and photon patients was 59.1% and 28.6%, respectively. Proton radiation therapy was also associated with a decreased risk of non–classic radiation–induced liver disease (odds ratio, 0.26; P = .03; 95% CI, 0.08-0.86). Development of nonclassic RILD at 3 months was associated with worse OS (adjusted hazard ratio, 3.83; P Conclusions Proton radiation therapy was associated with improved survival, which may be driven by decreased incidence of posttreatment liver decompensation. Our findings support prospective investigations comparing proton versus photon ablative radiation therapy for HCC.

OBJECTIVE: We sought to identify potential radiologic and serologic markers of pancreatic tumor response to therapy, using pathologic major response (pMR) as the objective endpoint. BACKGROUND: We previously demonstrated that a pMR to preoperative therapy, defined as detection of

Pancreatic ductal adenocarcinoma (PDAC) is a deadly cancer that progresses without any symptom, and oftentimes, it is detected at an advanced stage. The lack of prior symptoms and effective treatments have created a knowledge gap in the management of this lethal disease. This issue can be addressed by developing novel noninvasive imaging-based biomarkers in PDAC. We explored in vivo hyperpolarized (HP) 13C MRS of pyruvate to lactate conversion and ex vivo 1H NMR spectroscopy in a panel of well-annotated patient-derived PDAC xenograft (PDXs) model and investigated the correlation between aberrant glycolytic metabolism and aggressiveness of the tumor. Real-time metabolic imaging data demonstrate the immediate intracellular conversion of HP 13C pyruvate to lactate after intravenous injection interrogating upregulated lactate dehydrogenase (LDH) activity in aggressive PDXs. Total ex vivo lactate measurement by 1H NMR spectroscopy showed a direct correlation with in vivo dynamic pyruvate-to-lactate conversion and demonstrated the potential of dynamic metabolic flux as a biomarker of total lactate concentration and aggressiveness of the tumor. Furthermore, the metabolite concentrations were very distinct among all four tumor types analyzed in this study. Overexpression of LDH-A and hypoxia-inducible factor (HIF-1α) plays a significant role in the conversion kinetics of HP pyruvate-to-lactate in tumors. Collectively, these data identified aberrant metabolic characteristics of pancreatic cancer PDXs and could potentially delineate metabolic targets for therapeutic intervention. Metabolic imaging with HP pyruvate and NMR metabolomics may enable identification and classification of aggressive subtypes of patient-derived xenografts. Translation of this real-time metabolic technique to the clinic may have the potential to improve the management of patients at high risk of developing pancreatic diseases.

When pancreatic cancer cannot be removed surgically, patients frequently experience morbidity and death from progression of their primary tumor. Radiation therapy (RT) cannot yet substitute for an operation because radiation causes fatal bleeding and ulceration of the nearby stomach and intestines before achieving tumor control. There are no FDA-approved medications that prevent or reduce radiation-induced gastrointestinal injury. Here, we overcome this fundamental problem of anatomy and biology with the use of the oral EGLN inhibitor FG-4592, which selectively protects the intestinal tract from radiation toxicity without protecting tumors. A total of 70 KPC mice with autochthonous pancreatic tumors received oral FG-4592 or vehicle control ± ablative RT to a cumulative 75 Gy administered in 15 daily fractions to a limited tumor field. Although ablative RT reduced complications from local tumor progression, fatal gastrointestinal bleeding was observed in 56% of mice that received high-dose RT with vehicle control. However, radiation-induced bleeding was completely ameliorated in mice that received high-dose RT with FG-4592 (0% bleeding, P < 0.0001 compared with vehicle). Furthermore, FG-4592 reduced epithelial apoptosis by half (P = 0.002) and increased intestinal microvessel density by 80% compared with vehicle controls. EGLN inhibition did not stimulate cancer growth, as treatment with FG-4592 alone, or overexpression of HIF2 within KPC tumors independently improved survival. Thus, we provide a proof of concept for the selective protection of the intestinal tract by the EGLN inhibition to enable ablative doses of cytotoxic therapy in unresectable pancreatic cancer by reducing untoward morbidity and death from radiation-induced gastrointestinal bleeding. Significance: Selective protection of the intestinal tract by EGLN inhibition enables potentially definitive doses of radiation therapy. This might allow radiation to be a surgical surrogate for unresectable pancreatic cancer.

The vast majority of patients with pancreatic ductal adenocarcinoma (PDAC) presents with symptomatic, surgically unresectable disease. While the goal of early detection of PDAC is laudable, and likely to result in significant improvement in overall survival, the relatively low prevalence of PDAC renders general population screening infeasible. The challenges of early detection include identification of at-risk individuals in the general population who would benefit from longitudinal surveillance programs, and appropriate biomarker and imaging-based modalities utilized for PDAC surveillance in such cohorts. In recent years, various subgroups at higher than average risk for PDAC have been identified, including those with familial risk due to germline mutations, a history of pancreatitis, patients with mucinous pancreatic cysts, and elderly patients with new onset diabetes (NOD). The last two categories will be discussed at length in terms of the opportunities and challenges they present for PDAC early detection. We also discuss current and emerging imaging modalities that are critical to identifying early, potentially curable, PDAC in high-risk cohorts on surveillance.

Purpose To evaluate the effect of setup uncertainties including uncertainties between different breath holds (BH) and inter-fractional anatomical changes under CT-guided BH with intensity-modulated proton therapy (IMPT) in patients with liver cancer. Methods and materials This retrospective study considered 17 patients with liver tumors who underwent feedback-guided BH (FGBH) IMRT treatment with daily CT-on-rail imaging. Planning CT images were acquired at simulation using FGBH, and FGBH CT-on-rail images were also acquired prior to each treatment. Selective robust IMPT plans were generated using planning CT and re-calculated on each daily CT-on-rail image. Subsequently, the fractional doses were deformed and accumulated onto the planning CT according to the deformable image registration between daily and planning CTs. The doses to the target and organs at risk (OARs) were compared between IMRT, planned IMPT, and accumulated IMPT doses. Results For IMPT plans, the mean of D98% of CTV for all 17 patients was slightly reduced from the planned dose of 68.90 ± 1.61 Gy to 66.48 ± 1.67 Gy for the accumulated dose. The target coverage could be further improved by adjusting planning techniques. The dose–volume histograms of both planned and accumulated IMPT doses showed better sparing of OARs than that of the IMRT. Conclusions IMPT with FGBH and CT-on-rail guidance is a robust treatment approach for liver tumor cases.

BACKGROUNDPancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies, with unpredictable responses to chemotherapy. Approaches to assay patient tumors before treatment and identify effective treatment regimens based on tumor sensitivities are lacking. We developed an organoid-based platform (OBP) to visually quantify patient-derived organoid (PDO) responses to drug treatments and associated tumor-stroma modulation for personalized PDAC therapy.METHODSWe retrospectively quantified apoptotic responses and tumor-stroma cell proportions in PDOs via 3D immunofluorescence imaging through annexin A5, α-smooth muscle actin (α-SMA), and cytokeratin 19 (CK-19) levels. Simultaneously, an ex vivo organoid drug sensitivity assay (ODSA) was used to measure responses to standard-of-care regimens. Differences between ODSA results and patient tumor responses were assessed by exact McNemar's test.RESULTSImmunofluorescence signals, organoid growth curves, and Ki-67 levels were measured and authenticated through the OBP for up to 14 days. ODSA drug responses were not different from patient tumor responses, as reflected by CA19-9 reductions following neoadjuvant chemotherapy (P = 0.99). PDOs demonstrated unique apoptotic and tumor-stroma modulation profiles (P0.0001). α-SMA/CK-19 ratio levels of more than 1.0 were associated with improved outcomes (P = 0.0179) and longer parental patient survival by Kaplan-Meier analysis (P = 0.0046).CONCLUSIONHeterogenous apoptotic drug responses and tumor-stroma modulation are present in PDOs after standard-of-care chemotherapy. Ratios of α-SMA and CK-19 levels in PDOs are associated with patient survival, and the OBP could aid in the selection of personalized therapies to improve the efficacy of systemic therapy in patients with PDAC.FUNDINGNIH/National Cancer Institute grants (K08CA218690, P01 CA117969, R50 CA243707-01A1, U54CA224065), the Skip Viragh Foundation, the Bettie Willerson Driver Cancer Research Fund, and a Cancer Center Support Grant for the Flow Cytometry and Cellular Imaging Core Facility (P30CA16672).

The Elliott Wave principle is a time-honored, oft-used method for predicting variations in the financial markets. It is based on the notion that human emotions drive financial decisions. In the fight against the COVID-19 global pandemic, human emotions are similarly decisive, for instance in that they determine one’s willingness to be vaccinated, and/or to follow preventive measures including the personal wearing of masks, the application of social distancing protocols, and frequent handwashing. On this basis, we postulated that the Elliott Wave Principle may similarly be used to predict the future evolution of the COVID-19 pandemic. We demonstrated that this method reproduces the data pattern for various countries and the world (daily new cases). Potential scenarios were then extrapolated, from the best-case corresponding to a rapid, full vaccination of the population, to the utterly disastrous case of slow vaccination, and poor adherence to preventive protocols.

Checkpoint inhibitor therapy of cancer has led to markedly improved survival of a subset of patients in multiple solid malignant tumor types, yet the factors driving these clinical responses or lack thereof are not known. Here we present a translational mathematical model dependent on three key parameters for describing efficacy of checkpoint inhibitors in human cancer: tumor growth rate (α), tumor immune infiltration (Λ), and immunotherapy-mediated amplification of anti-tumor response (µ). The model was validated by fitting it to a compiled clinical tumor response dataset (n = 189 patients) obtained from published anti-PD-1 and anti-PD-L1 clinical trials, and then validated on an additional validation cohort (n = 64 patients) obtained from our in-house clinical trials. The derived parameters Λ and µ were both significantly different between responding versus non-responding patients. Of note, our model appropriately classified response in 81.4% of patients by using only tumor volume measurements and within two months of treatment initiation in a retrospective analysis. The model reliably predicted clinical response to the PD-1/PD-L1 class of checkpoint inhibitors across multiple solid malignant tumor types. Comparison of model parameters to immunohistochemical measurement of PD-L1 and CD8+ T cells confirmed robust relationships between model parameters and their underlying biology, demonstrating reliable methods to inform model parameters directly from biopsy samples, which are conveniently obtainable as early as the start of treatment. Together, these results suggest that the model parameters may serve as early and robust biomarkers of the efficacy of checkpoint inhibitor therapy on an individualized per-patient basis.SIGNIFICANCECheckpoint inhibitors have revolutionized cancer immunotherapy, but only a subset of patients with solid tumors responds clinically. The ability to predict tumor responses a priori or soon after starting therapy would allow for personalized and timely adaptive clinical applications of checkpoint inhibitor- based immunotherapy in patients. By applying a mechanistic mathematical model, we show that checkpoint inhibitor therapeutic effectiveness is accurately predictable in most patients within two months after treatment initiation. Our method may be implemented directly into clinical practice, as it relies on standard-of-care imaging and pathology. If successful in prospective studies, this model will improve selection of cancer patients for checkpoint inhibitor therapy, and perhaps for other forms of humoral- or cell-based immunotherapy.

IntroductionPancreatic adenocarcinoma (PAC) has some of the worst treatment outcomes for any solid tumor. PAC creates substantial difficulty for effective treatment with traditional RT delivery strategies primarily secondary to its location and limited visualization using CT. Several of these challenges are uniquely addressed with MR-guided RT. We sought to summarize and place into context the currently available literature on MR-guided RT specifically for PAC.MethodsA literature search was conducted to identify manuscript publications since September 2014 that specifically used MR-guided RT for the treatment of PAC. Clinical outcomes of these series are summarized, discussed, and placed into the context of the existing pancreatic literature. Multiple international experts were involved to optimally contextualize these publications.ResultsOver 300 manuscripts were reviewed. A total of 6 clinical outcomes publications were identified that have treated patients with PAC using MR guidance. Successes, challenges, and future directions for this technology are evident in these publications. MR-guided RT holds theoretical promise for the treatment of patients with PAC. As with any new technology, immediate or dramatic clinical improvements associated with its use will take time and experience. There remain no prospective trials, currently publications are limited to small retrospective experiences. The current level of evidence for MR guidance in PAC is low and requires significant expansion. Future directions and ongoing studies that are currently open and accruing are identified and reviewed.ConclusionsThe potential promise of MR-guided RT for PAC is highlighted, the challenges associated with this novel therapeutic intervention are also reviewed. Outcomes are very early, and will require continued and long term follow up. MR-guided RT should not be viewed in the same fashion as a novel chemotherapeutic agent for which dosing, administration, and toxicity has been established in earlier phase studies. Instead, it should be viewed as a novel procedural intervention which must be robustly tested, refined and practiced before definitive conclusions on the potential benefits or detriments can be determined. The future of MR-guided RT for PAC is highly promising and the potential implications on PAC are substantial.

BackgroundGlucose-regulated protein 78 (GRP78) plays an essential role in protein folding, transportation, and degradation, thus regulates ER homeostasis and promotes cell survival, proliferation and invasion. GRP78 expression in PDAC patients who received neoadjuvant therapy has not been reported.MethodsThis retrospective study of resected PDAC patients included 125 patients treated with neoadjuvant therapy (NAT) and 140 patients treated with surgery first (SF). The expression of GRP78 was evaluated by immunohistochemistry on tissue microarrays and the results were correlated with clinicopathologic parameters and survival.ResultsGRP78 expression was higher in SF patients compared to NAT patients (P&nbsp

PURPOSE/OBJECTIVE(S) Few studies have long-term follow-up assessing patient-reported outcomes (PROs) after intensity-modulated radiation therapy (IMRT)-based chemoradiation (CRT) for squamous cell carcinoma of the anus (SCCA). There is poor agreement between physician-graded toxicity and PROs regarding quality of life (QOL) in patients with SCCA. Therefore, we surveyed SCCA survivors ≥ 2 years out from CRT with validated PRO instruments assessing bowel, bladder, and sexual function. MATERIALS/METHODS We identified 248 patients with SCCA treated with definitive IMRT-based CRT at a large tertiary cancer center from 2010-2018, who were alive and without recurrence. Patients were asked to complete five PRO instruments: Fecal Incontinence QOL Scale (FIQOL), Low Anterior Resection Syndrome Score (LARS), International Consultation on Incontinence Questionnaire (ICIQ), male and female lower urinary tract symptoms (MLUTS and FLUTS, respectively), International Index of Erectile Function (IIEF), and Female Sexual Function Index (FSFI). FIQOL, LARS, IIEF, and FSFI scores were dichotomized and logistic regression used to identify predictors of QOL scores. RESULTS One hundred eight (44%) patients completed the PROs. Respondents' median [interquartile range, (IQR)] age was 66 [59-72] years, 80% were female, and 95% were white. Median [IQR] gross tumor volume (GTV) was 45 [27-71] cc; dose to GTV was 50 Gray (Gy), 54 Gy and 58 Gy in 25%, 53%, and 22%, respectively. Median [IQR] time from CRT was 51 [37-84] months. Median [IQR] FIQOL score was 14.3/20 [11.2-16.1]; higher is better. Larger GTV size (OR 0.99; P = 0.03) was associated with lower FIQOL score. Sixty-one (56%) patients met major LARS criteria. There was a trend towards a higher incidence of major LARS with GTV dose ≥ 54 Gy (OR 2.39; P = 0.08). Men had median [IQR] ICIQ MLUTS voiding and incontinence scores of 5/20 [2-6] and 1/24 [1-3], respectively. Women had median [IQR] ICIQ FLUTS voiding and incontinence scores of 1/12 [1-3] and 5/20 [3-8], respectively; higher is worse. Fifty-nine (55%) patients reported being sexually active in the last month. Men had a median [IQR] IIEF score of 14/25 [6-19]; higher is better. Only age (OR 1.17; P = 0.04) was significantly associated with IIEF ≤ 11 (moderate or severe ED). Women had a median [IQR] FSFI score of 20.2/26 [13.6-24.9]; higher is better. Age < 65 was associated with sexual dysfunction, defined as FSFI < 26.55 (OR, 5.5; P = 0.04). Forty (37%) patients disagreed or strongly disagreed that they were prepared for long-term side effects. Seventy (65%) patients agreed or strongly agreed that educational materials would have been helpful. CONCLUSION SCCA survivors experience significant long-term bowel and sexual toxicities from modern CRT. Larger tumors and higher RT doses may be associated with worse function. Interventions to reduce toxicities and improve patient education are needed.

PURPOSE/OBJECTIVE(S) Current GI toxicity models are limited by the uncertainty in the estimated delivered dose used to develop the models. The purpose of this study is to assess the benefit of harnessing deep learning and biomechanical models to improve the understanding of the dose-toxicity relationship. MATERIALS/METHODS Retrospective dose accumulation was conducted on 75 patients with primary and metastatic liver cancer treated with external beam radiotherapy guided by daily CT-on-rails (CTOR), based on a novel deformable image registration (DIR) approach that applies biomechanical model-based and intensity-based DIR inside and outside the liver, respectively. The liver was auto-segmented on all images using a clinically validated 2D deep learning model. On a sub-cohort, the combination of stomach and duodenum region of interest (GI ROI) was auto-contoured using a 3D UNet model trained independently on 102 patients. These contours were compared to physician-drawn contours on CTOR, using Dice similarity coefficient (DSC), mean distance to agreement (DTA), Hausdorff distance (HD), and planned dose metrics. Intra-observer variability was evaluated. Doses were converted to equivalent dose in 2Gy fractions (EQD2) for analysis (α/β = 3.5). Differences between planned and delivered dose were calculated, as well as GI ROI daily dose variation. Toxicity probability was calculated based on previously developed accumulated dose normal tissue complication probability (NTCP) models for duodenum and stomach. RESULTS Average (SD) DSC, DTA, and HD between the deep learning model and physician-drawn GI ROI were 0.9 (0.1), 0.2 (0.1) cm, and 2.4 (2.2) cm; intra-observer values were 0.9 (0.0), 0.1 (0.0) cm, and 2.3 (0.8) cm, P > 0.1. Average differences in volume (SD), D50 (SD), and D1 (SD) between the AI model and physician-drawn contours were 25.0 (36.7) cc, 0.6 (1.1) Gy, and 0.5 (0.2) Gy; intra-observer values were 7.1 (4.5) cc, 0.2 (0.3) Gy and 0.3 (0.3) Gy, P > 0.1. Average planned and accumulated D1 (EQD2) to the GI ROI were 28.1 Gy and 26.6 Gy, respectively. These distributions were significantly different (P < 0.01), with differences ranging from 0.2 Gy to 2.9 Gy. Daily D1 to the GI ROI varied by up to 47% (average 25%). For 38% of patients, relative differences in NTCP based on planned and accumulated dose were greater than 50%. Compared to planned dose, 63% of the patients had lower NTCP with accumulated dose, and 13% had higher NTCP. CONCLUSION Variability between AI-based and physician-drawn stomach and duodenum segmentation was equivalent to intra-observer variability. Accumulated dose showed statistically significant differences from planned dose for the stomach and duodenum leading to meaningful differences in NTCP. The daily variability in the maximum dose varied by an average of +/- 25%, demonstrating the potential to optimize daily fractionation based on anatomical configuration of the day.

PURPOSE/OBJECTIVE(S) Radiotherapy (RT) is increasingly used in advanced hepatocellular carcinoma (HCC), providing excellent local control. Regional and distant failures are common though, and radiation-induced liver disease (RILD) and post-RT lymphopenia have been shown to correlate with survival. In this study, we develop machine learning (ML) models to predict these endpoints and validate them using an independent dataset. MATERIALS/METHODS We developed Cox regression and random survival forests to estimate survival, and both linear (logistic regression) and nonlinear discriminant ML models (support vector machines and gradient boosted trees) for four binary endpoints: 1-year survival, non-local failure within 1 year (NLF1y), RILD defined as 2+ increase in Child Pugh score and lymphopenia (count < 0.5 109/L). Metrics include c-index for survival analysis, area under the ROC curve (AUC) and accuracy in the 10/20% highest risk groups for discriminant analysis. The models training considered 21 clinical and dosimetric variables evaluated in a nested cross-validation approach for feature selection and hyperparameter tuning. After locking the models, we used an unseen independent dataset for external validation without any further calibration. A study analysis plan detailing methodology was published before access to the external validation set. RESULTS 207 HCC patients treated at a single institution between 2008 and 2019 were used for model training and 143 patients from a different institution for external validation. The survival models discriminated well between low- and high-risk groups (Harrell's c = 0.72), patients classified above median risk had a significantly higher risk of death (HR = 3.2 (95% CI [2.1-4.9]), P < 0.001) with 9.4 months observed median survival compared to 33.2 months for the low-risk group. Discriminatory power for top versus bottom survival quartile increased to HR = 6.1 [3.3-11], median survival 5.4 vs 42.5 months. Binary classification performance for all endpoints was consistent between training and validation with an external AUC of 0.79 for 1-year survival (internal 0.75), and 0.64-0.68 for the other endpoints (internal 0.53-0.71). The models predict NLF1y in high/very-high risk groups (87/100% accuracy) and lymphopenia in the very high-risk group (65-85% accuracy). Notably platelet count is selected by all generative classifiers of RILD, indicating interaction with known predictors. CONCLUSION Independent validation of the models demonstrates the ability to accurately stratify patients by survival and discriminant endpoints with comparable performance on external validation, which underscores good generalizability. High prediction accuracy for sub-groups at high risk of non-local failure and lymphopenia could enable treatment modification in specific cases, while no approach reliably predicted RILD.

Human papillomavirus (HPV) infection causes 600,000 new cancers worldwide each year. HPV-related cancers express the oncogenic proteins E6 and E7, which could serve as tumor-specific antigens. It is not known whether immunity to E6 and E7 evolves during chemoradiotherapy (CRT) or affects survival. We used functional T-cell assays to identify candidate HPV-specific T-cells and T- cell motifs common across 86 patients with HPV-related cancers. These HPV-specific clones and E7-related motifs expanded over the course of treatment, whereas non-HPV-specific T-cells did not. In HPV16+ patients, improved recurrence-free survival was associated with this HPV-responsive T-cell expansion during CRT.

Purpose Localized pancreatic cancer is commonly treated with stereotactic body radiation therapy (SBRT), which often requires the placement of fiducial markers. We compared the clinical outcomes of patients with and without fiducial markers. Methods and Materials We retrospectively collected data on patients with pancreatic cancer treated with neoadjuvant SBRT at a single institution. Patients were divided into 2 groups based on the placement of a fiducial marker. Local recurrence was the primary outcome. Time to event endpoints were analyzed using COX regression. Results We included 96 patients with unresectable pancreatic cancer: 46 patients (47.9%) did not have a fiducial marker, and 50 patients (52.1%) had a fiducial placed. Patients in the fiducial group were older and had more locally advanced pancreatic cancer compared with those who did not have a fiducial placed. Most patients in both groups (92.7%) received chemotherapy before SBRT treatment. SBRT was delivered to a median of 36 Gy over 5 fractions in the no-fiducial group, and 38 Gy over 5 fractions in the fiducial group. At a median follow-up of 20 months, local recurrence was similar irrespective of fiducial placement (adjusted hazard ratio [aHR] 0.6, 95% CI 0.3-1.3, P = .59). Furthermore, no difference in overall survival was noted between the 2 groups (aHR 0.8, 95% CI 0.3-1.9, P = .65). In patients who eventually underwent surgery post-SBRT, no difference in surgical margins (P = .40) or lymphovascular invasion (P = .76) was noted between the 2 groups. No patient developed acute pancreatitis after fiducial placement. Conclusions Our data suggest that the use of fiducial markers does not negatively affect clinical outcomes in patients with localized pancreatic cancer. Prospective confirmation of our results is still needed.

Purpose The deformable nature of the liver can make focal treatment challenging and is not adequately addressed with simple rigid registration techniques. More advanced registration techniques can take deformations into account (eg, biomechanical modeling) but require segmentations of the whole liver for each scan, which is a time-intensive process. We hypothesize that fully convolutional networks can be used to rapidly and accurately autosegment the liver, removing the temporal bottleneck for biomechanical modeling. Methods and Materials Manual liver segmentations on computed tomography scans from 183 patients treated at our institution and 30 scans from the Medical Image Computing & Computer Assisted Intervention challenges were collected for this study. Three architectures were investigated for rapid automated segmentation of the liver (VGG-16, DeepLabv3 +, and a 3-dimensional UNet). Fifty-six cases were set aside as a final test set for quantitative model evaluation. Accuracy of the autosegmentations was assessed using Dice similarity coefficient and mean surface distance. Qualitative evaluation was also performed by 3 radiation oncologists on 50 independent cases with previously clinically treated liver contours. Results The mean (minimum-maximum) mean surface distance for the test groups with the final model, DeepLabv3 +, were as follows: μContrast(N = 17): 0.99 mm (0.47-2.2), μNon_Contrast(N = 19)l: 1.12 mm (0.41-2.87), and μMiccai(N = 30)t: 1.48 mm (0.82-3.96). The qualitative evaluation showed that 30 of 50 autosegmentations (60%) were preferred to manual contours (majority voting) in a blinded comparison, and 48 of 50 autosegmentations (96%) were deemed clinically acceptable by at least 1 reviewing physician. Conclusions The autosegmentations were preferred compared with manually defined contours in the majority of cases. The ability to rapidly segment the liver with high accuracy achieved in this investigation has the potential to enable the efficient integration of biomechanical model-based registration into a clinical workflow.

The Elliott Wave principle is a time-honored, oft-used method for predicting variations in the financial markets. It is based on the notion that human emotions drive financial decisions. In the fight against COVID-19, human emotions are similarly decisive, for instance in that they determine one’s willingness to be vaccinated, and/or to follow preventive measures including the wearing of masks, the application of social distancing protocols, and frequent handwashing. On this basis, we postulated that the Elliott Wave Principle may similarly be used to predict the future evolution of the COVID-19 pandemic. We demonstrated that this method reproduces the data pattern especially well for USA (daily new cases). Potential scenarios were then extrapolated, from the best-case corresponding to a rapid, full vaccination of the population, to the utterly disastrous case of slow vaccination, and poor adherence to preventive protocols.

Treatment options in locally advanced hepatocellular carcinoma (HCC) have evolved considerably over the past few years with the recent approval of multiple systemic therapies and significant advances in locoregional therapy. Given the poor prognosis for patients with unresectable HCC, there is significant interest in rationally designed combination therapies. This article reviews the treatment options available to patients with locally advanced HCC and discusses the rationale, ongoing trials, and future prospects for combining locoregional and systemic therapy in both the definitive and neoadjuvant settings.

Previously, we characterized qualitative imaging-based subtypes of pancreatic ductal adenocarcinoma (PDAC) on computed tomography (CT) scans. Conspicuous (high delta) PDAC tumors are more likely to have aggressive biology and poorer clinical outcomes compared to inconspicuous (low delta) tumors. Here, we developed a quantitative classification of this imaging-based subtype (quantitative delta, q-delta). Retrospectively, baseline pancreatic protocol CT scans of three cohorts (cohort#1 = 101, cohort#2 = 90 and cohort#3 = 16 [external validation]) of patients with PDAC were qualitatively classified into high and low delta. We used a voxel-based method to volumetrically quantify tumor enhancement while referencing normal-pancreatic-parenchyma and used machine learning-based analysis to build a predictive model. In addition, we quantified the stromal content using hematoxylin- and eosin-stained treatment-na&iuml, ve PDAC sections. Analyses revealed that PDAC quantitative enhancement values are predictive of the qualitative delta scoring and were used to build a classification model (q-delta). Compared to high q-delta, low q-delta tumors were associated with improved outcomes, and the q-delta class was an independent prognostic factor for survival. In addition, low q-delta tumors had higher stromal content and lower cellularity compared to high q-delta tumors. Our results suggest that q-delta classification provides a clinically and biologically relevant tool that may be integrated into ongoing and future clinical trials.

Evaluate utility of dual energy CT iodine material density images to identify preoperatively nodal positivity in pancreatic cancer patients who underwent neoadjuvant therapy.This IRB approved retrospective study evaluated 62 patients between 2012 and 2016 with proven pancreatic ductal adenocarcinoma, who underwent neoadjuvant therapy, tumor resection and both baseline and preoperative assessment with pancreatic multiphasic rapid switching dual energy CT. Three radiologists in consensus identified on imaging nodes 0.5 cm in short axis, evaluated nodal morphology, size and on each phase density in HU, and concentrations on iodine material density images normalized to the aorta.Of 62 patients, 33 were N0, 20 N1, and 9 N2. Total of 145 lymph nodes were evaluated, with average number of nodes per anatomic site ranging from 1.3 (body tumors) to 5 (uncinate) versus average of 24 and 30 nodes recovered respectively at surgery. Most (N = 44) were pancreatic head tumors. For all patients, regardless of site of primary tumor, the minimum measured iodine value of all of a patient's measured nodes taken as a group on preoperative studies, as normalized to the aorta, was significant at P = 0.041 value in differentiating N0 from N1/2 and ROC analysis showed an AUC of 0.67. With a cutoff of 0.2857, sensitivity was 0.78 and specificity was 0.58, with values 0.2857 indicative of N1/2. Node morphology and changes in nodal size weren't statistically significant.The dual energy based minimum normalized iodine value of all nodes in the surgical field on preoperative studies has modest utility in differentiating N0 from N1/2, and generally outperformed conventional features for identifying nodal metastases.

Cancers are highly complex ecosystems composed of molecularly distinct sub-populations of tumor cells, each exhibiting a unique spectrum of genetic features and phenotypes, and embedded within a complex organ context. To substantially improve clinical outcomes, there is a need to comprehensively define inter- and intra-tumor phenotypic diversity, as well as to understand the genetic dependencies that underlie discrete molecular subpopulations. To this end, we integrated CRISPR-based co-dependency annotations with a tissue-specific co-expression network developed from patient-derived models to establish CoDEX, a framework to quantitatively associate gene-cluster patterns with genetic vulnerabilities in pancreatic ductal adenocarcinoma (PDAC). Using CoDEX, we defined multiple prominent anticorrelated gene-cluster signatures and specific pathway dependencies, both across genetically distinct PDAC models and intratumorally at the single-cell level. Of these, one differential signature recapitulated the characteristics of classical and basal-like PDAC molecular subtypes on a continuous scale. Anchoring genetic dependencies identified through functional genomics within the gene-cluster signature defined fundamental vulnerabilities associated with transcriptomic signatures of PDAC subtypes. Subtype-associated dependencies were validated by feature-barcoded CRISPR knockout of prioritized basal-like-associated genetic vulnerabilities (SMAD4, ILK, and ZEB1) followed by scRNAseq in multiple PDAC models. Silencing of these genes resulted in a significant and directional clonal shift toward the classical-like signature of more indolent tumors. These results validate CoDEX as a novel, quantitative approach to identify specific genetic dependencies within defined molecular contexts that may guide clinical positioning of targeted therapeutics.

Pancreatic ductal adenocarcinoma (PDAC) is almost uniformly fatal and characterized by early metastasis. Oncogenic KRAS mutations prevail in 95% of PDAC tumors and co-occur with genetic alterations in the TP53 tumor suppressor in nearly 70% of patients. Most TP53 alterations are missense mutations that exhibit gain-of-function phenotypes that include increased invasiveness and metastasis yet the extent of direct cooperation between KRAS effectors and mutant p53 remains largely undefined. We show that oncogenic KRAS effectors activate cyclic AMP responsive element binding protein 1 (CREB1) to allow physical interactions with mutant p53 that hyperactivate multiple pro-metastatic transcriptional networks. Specifically, mutant p53 and CREB1 upregulate the pro-metastatic, pioneer transcription factor, FOXA1, activating its transcriptional network while promoting WNT/β-catenin signaling, together driving PDAC metastasis. Pharmacologic CREB1 inhibition dramatically reduced FOXA1 and β-catenin expression and dampened PDAC metastasis, identifying a new therapeutic strategy to disrupt cooperation between oncogenic KRAS and mutant p53 to mitigate metastasis.

BackgroundPreviously, we characterized subtypes of pancreatic ductal adenocarcinoma (PDAC) on computed-tomography (CT) scans, whereby conspicuous (high delta) PDAC tumors are more likely to have aggressive biology and poorer clinical outcomes compared to inconspicuous (low delta) tumors. Here, we hypothesized that these imaging-based subtypes would exhibit different growth-rates and distinctive metabolic effects in the period prior to PDAC diagnosis.Materials and methodsRetrospectively, we evaluated 55 patients who developed PDAC as a second primary cancer and underwent serial pre-diagnostic (T0) and diagnostic (T1) CT-scans. We scored the PDAC tumors into high and low delta on T1 and, serially, obtained the biaxial measurements of the pancreatic lesions (T0-T1). We used the Gompertz-function to model the growth-kinetics and estimate the tumor growth-rate constant (α) which was used for tumor binary classification, followed by cross-validation of the classifier accuracy. We used maximum-likelihood estimation to estimate initiation-time from a single cell (10-6 mm3) to a 10 mm3 tumor mass. Finally, we serially quantified the subcutaneous-abdominal-fat (SAF), visceral-abdominal-fat (VAF), and muscles volumes (cm3) on CT-scans, and recorded the change in blood glucose (BG) levels. T-test, likelihood-ratio, Cox proportional-hazards, and Kaplan-Meier were used for statistical analysis and p-value ResultsCompared to high delta tumors, low delta tumors had significantly slower average growth-rate constants (0.024 month−1 vs. 0.088 month−1, p−1. Leave-one-out-cross-validation showed 80% accuracy in predicting the delta-class (AUC=0.84). High delta tumors exhibited accelerated SAF, VAF, and muscle wasting (p ConclusionImaging-based subtypes of PDAC exhibit distinct growth, metabolic, and clinical profiles during the pre-diagnostic period. Our results suggest that heterogeneous disease biology may be an important consideration in early detection strategies for PDAC.

The purpose of this study was to quantitatively evaluate the visibility and artifacts of commercially available fiducial markers in order to optimize their selection for image-guided stereotactic body radiation therapy (SBRT). From six different vendors, we selected 11 fiducials commonly used in image-guided radiation therapy (IGRT); the fiducials varied in material composition (gold, platinum, carbon), shape (cylindrical, notched/linear, coiled, ball-like, step), and size measured in terms of diameter (0.28-1.0 mm) and length (3.0-20.0 mm). Each fiducial was centered in 4-mm bolus within a 13-cm-thick water-equivalent phantom. Fiducials were imaged with use of a simulation computed tomography (CT) scanner, a CT-on-rails system, and an onboard cone-beam CT system. Acquisition parameters were set according to clinical protocols. Visibility was assessed in terms of contrast and the Michelson visibility metric. Artifacts were quantified in terms of relative standard deviation and relative streak artifacts level (rSAL). Twelve radiation oncologists ranked each fiducial in terms of clinical usefulness. Contrast and artifacts increased with fiducial size. For CT imaging, maximum contrast (2722 HU) and artifacts (rSAL=2.69) occurred for the largest-diameter (0.75 mm) platinum fiducial. Minimum contrast (551 HU) and reduced artifacts (rSAL=0.65) were observed for the smallest-diameter (0.28 mm) gold fiducial. Carbon produced the least severe artifacts (rSAL = 0.29). The survey indicated that physicians preferred gold fiducials with a 0.35- to 0.43-mm diameter, 5- to 10-mm length, and a coiled or cylindrical shape that balanced contrast and artifacts. We evaluated 11 different fiducials in terms of visibility and artifacts. The results of this study may assist radiation oncologists who seek to maximize contrast, minimize artifacts, and/or balance contrast versus artifacts by fiducial selection., 22 pages

IMPORTANCE: Fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX) and gemcitabine plus nanoparticle albumin-bound (nab)–paclitaxel (GA) are first-line chemotherapy regimens for pancreatic cancer. Their relative efficacy in the setting of localized disease is unknown. OBJECTIVE: To evaluate radiographic and serologic measures of responses associated with first-line chemotherapy with FOLFIRINOX or GA, and to determine the association between these drug regimens, putative measures of response, and survival. DESIGN, SETTING, AND PARTICIPANTS: This case series assessed 485 consecutive patients who were diagnosed as having previously untreated localized pancreatic ductal adenocarcinoma at The University of Texas MD Anderson Cancer Center between January 1, 2010, and December 31, 2017, and who received at least 3 cycles of first-line chemotherapy with FOLFIRINOX or GA. The median (range) follow-up duration was 33 (2-28) months. EXPOSURES: Administration of FOLFIRINOX (285 patients [59%]) or GA (200 patients [41%]) as first-line chemotherapy. MAIN OUTCOMES AND MEASURES: Resection rate, radiographic metrics (Response Evaluation Criteria in Solid Tumors [RECIST], version 1.1, and change in tumor volume or anatomic staging), a serologic metric (serum cancer antigen 19-9 level), and overall survival after administration of first-line chemotherapy. RESULTS: In total, 485 patients (266 [55%] male) were included in the analysis. Patients treated with FOLFIRINOX were generally younger (median [range] age at diagnosis: 61 [30-81] vs 71 [36-89] years; P = .001) and had better performance status as indicated by the Eastern Cooperative Oncology Group scale (range 0-4, with lower numbers representing better performance) score of 2 or lower (274 patients [96%] vs 165 patients [82%] P = .001) but more invasive tumors than patients who received GA (91 [32%] vs 90 [45%] resectable tumors; P = .01). After propensity score matching to control for these biases, many objective serologic and radiographic metrics of response associated with administration of FOLFIRINOX or GA—including low rates of local tumor downstaging—did not differ. However, RECIST partial response was more common among patients treated with FOLFIRINOX (27 of 140 patients [19%]) than with GA (8 of 140 patients [6%]; P = .001). Moreover, (chemo)radiation (50% vs 34%; P = .001) was more commonly administered to and pancreatectomy (27% vs 16%; P = .01) was subsequently performed more frequently for patients initially treated with FOLFIRINOX. The overall survival duration of patients treated with either regimen was similar (hazard ratio, 1.48; 95% CI, 0.97-2.26; P = .07). CONCLUSIONS AND RELEVANCE: In this cohort of patients with localized pancreatic adenocarcinoma who received FOLFIRINOX or GA as their first line of therapy, FOLFIRINOX was associated with higher rates of RECIST partial response and subsequent pancreatectomy than GA, but the overall survival associated with these regimens was similar.

Radiomics, also known as quantitative imaging or texture analysis, involves extracting a large number of features traditionally unmeasured in conventional radiological cross-sectional images and converting them into mathematical models. This review describes this approach and its use in the evaluation of pancreatic cystic lesions (PCLs). This discipline has the potential of more accurately assessing, classifying, risk stratifying, and guiding the management of PCLs. Existing studies have provided important insight into the role of radiomics in managing PCLs. Although these studies are limited by the use of retrospective design, single center data, and small sample sizes, radiomic features in combination with clinical data appear to be superior to the current standard of care in differentiating cyst type and in identifying mucinous PCLs with high-grade dysplasia. Combining radiomic features with other novel endoscopic diagnostics, including cyst fluid molecular analysis and confocal endomicroscopy, can potentially optimize the predictive accuracy of these models. There is a need for multicenter prospective studies to elucidate the role of radiomics in the management of PCLs.

PURPOSE: Among patients with anal cancer, chemoradiotherapy is often associated with toxicities that diminish quality of life. We describe the GI-related patient-reported outcomes (PROs) of patients with anal cancer receiving chemoradiotherapy to improve patient-physician communication. METHODS: We prospectively followed patients with nonmetastatic squamous cell carcinoma of the anal canal who received definitive chemoradiotherapy. Patients completed the bowel subdomain of the Expanded Prostate Cancer Index Composite (EPIC) questionnaire before treatment and at 4 subsequent timepoints. We used the paired Wilcoxon test to compare EPIC scores at different times. RESULTS: The study included 21 patients; median age was 57 years. Most patients (52%) had T2 and either N0 or N1 disease (81%). Most patients (91%) received chemotherapy with cisplatin-fluorouracil and either intensity-modulated radiotherapy or volumetric modulated arc therapy. Compared with the patients’ median overall summary score at baseline (66), their median score at 1 week (82) was higher ( P = .009), whereas their median score at 5 weeks (54) was lower ( P = .025). The patients’ median overall summary score at baseline and at 3 months did not differ ( P = .919). Three months after radiotherapy, most patients reported minimal adverse effects compared with baseline. CONCLUSION: The GI-related PROs of patients with anal cancer tend to fluctuate during radiotherapy but return to baseline by 3 months, at which time most patients report few or no residual adverse effects. We provide a clear timeline of GI acute toxicity using sequential PRO measurements that will improve patient-physician communication regarding expectations for cancer treatment.

Local recurrences can sometimes occur after prior radiotherapy for abdominal and pelvic cancers. The management of these patients can be quite complex. We present a case of recurrent pancreatic cancer after prior chemoradiation and discuss various management options, with a focus on different approaches to reirradiation.

A mathematical model of checkpoint inhibitor immunotherapy yields patient-specific prognosis of tumor kill and patient survival., We present a mechanistic mathematical model of immune checkpoint inhibitor therapy to address the oncological need for early, broadly applicable readouts (biomarkers) of patient response to immunotherapy. The model is built upon the complex biological and physical interactions between the immune system and cancer, and is informed using only standard-of-care CT. We have retrospectively applied the model to 245 patients from multiple clinical trials treated with anti–CTLA-4 or anti–PD-1/PD-L1 antibodies. We found that model parameters distinctly identified patients with common (n = 18) and rare (n = 10) malignancy types who benefited and did not benefit from these monotherapies with accuracy as high as 88% at first restaging (median 53 days). Further, the parameters successfully differentiated pseudo-progression from true progression, providing previously unidentified insights into the unique biophysical characteristics of pseudo-progression. Our mathematical model offers a clinically relevant tool for personalized oncology and for engineering immunotherapy regimens.

While plasma concentration kinetics has traditionally been the predictor of drug pharmacological effects, it can occasionally fail to represent kinetics at the site of action, particularly for solid tumors. This is especially true in the case of delivery of therapeutic macromolecules (drug‐loaded nanomaterials or monoclonal antibodies), which can experience challenges to effective delivery due to particle size‐dependent diffusion barriers at the target site. As a result, disparity between therapeutic plasma kinetics and kinetics at the site of action may exist, highlighting the importance of target site concentration kinetics in determining the pharmacodynamic effects of macromolecular therapeutic agents. Assessment of concentration kinetics at the target site has been facilitated by non‐invasive in vivo imaging modalities. This allows for visualization and quantification of the whole‐body disposition behavior of therapeutics that is essential for a comprehensive understanding of their pharmacokinetics and pharmacodynamics. Quantitative non‐invasive imaging can also help guide the development and parameterization of mathematical models for descriptive and predictive purposes. Here, we present a review of the application of state‐of‐the‐art imaging modalities for quantitative pharmacological evaluation of therapeutic nanoparticles and monoclonal antibodies, with a focus on their integration with mathematical models, and identify challenges and opportunities. This article is categorized under:Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic DiseaseDiagnostic Tools > in vivo Nanodiagnostics and ImagingNanotechnology Approaches to Biology > Nanoscale Systems in Biology, Pharmacological evaluation of nanoparticles and antibodies performed through quantitative imaging‐guided mathematical models.

Highlights • The use of oral stents during RT was associated with reduced late morbidity. • OPC patients with bilateral RT and tongue-depressing stents had less dysphagia. • Patients with unilateral RT and tongue-deviating stent had better taste/appetite., Objectives To evaluate whether the use of oral stents during intensity modulated radiation therapy (IMRT) for oropharyngeal cancer (OPC) is associated with long-term patient reported symptoms. Materials and methods Data was obtained from a prospective observational study of disease-free head and neck cancer survivors. Radiation-associated patient reported symptoms were assessed using the MD Anderson Symptom Inventory Head and Neck module (MDASI-HN). Scores of ≥5 (11-point Likert scale, 0-10) were considered moderate/severe. Stratification was performed regarding IMRT volume (uni- versus bilateral neck) and stent utilization, with non-parametric analyses between groups. Results 462 OPC survivors formed the cohort (54% tonsil, 46% base of tongue primaries). A tongue-deviating stent was used in 17%, tongue-depressing stent in 46%, and no stent in 37%. Median prescribed dose to the high dose clinical target volume was 66.0 Gy. Median follow-up from RT to MDASI-HN assessment was 68 months. Twenty percent had received unilateral neck RT (all had tonsil primaries), in whom a significant improvement in the proportion of patients with moderate/severe taste impairment (2% vs. 15%, p = 0.047) and lack of appetite (0% vs. 9%, p = 0.019) was associated with the use of tongue-deviating stents compared to no oral stent. In those who had received bilateral neck RT, a significant improvement in the proportion of patients with moderate/severe difficulty swallowing/chewing was associated with use of a tongue-depressing stent (21% vs. 31% without oral stent, p = 0.013). Conclusion Disease-site specific select use of oral stents during IMRT was associated with reduced long-term patient reported symptoms in OPC survivors.

Pancreatic ductal adenocarcinoma is most frequently detected at an advanced stage. Such late detection restricts treatment options and contributes to a dismal 5-year survival rate of 3-15%. Pancreatic ductal adenocarcinoma is relatively uncommon and screening of the asymptomatic adult population is not feasible or recommended with current modalities. However, screening of individuals in high-risk groups is recommended. Here, we review groups at high risk for pancreatic ductal adenocarcinoma, including individuals with inherited predisposition and patients with pancreatic cystic lesions. We discuss studies aimed at finding ways of identifying pancreatic ductal adenocarcinoma in high-risk groups, such as among individuals with new-onset diabetes mellitus and people attending primary and secondary care practices with symptoms that suggest this cancer. We review early detection biomarkers, explore the potential of using social media for detection, appraise prediction models developed using electronic health records and research data, and examine the application of artificial intelligence to medical imaging for the purposes of early detection.

Purpose Response assessment of radiotherapy for the treatment of intrahepatic cholangiocarcinoma (IHCC) across longitudinal images is challenging due to anatomical changes. Advanced deformable image registration (DIR) techniques are required to correlate corresponding tissues across time. In this study, the accuracy of five commercially available DIR algorithms in four treatment planning systems (TPS) was investigated for the registration of planning images with posttreatment follow-up images for response assessment or re-treatment purposes. Methods Twenty-nine IHCC patients treated with hypofractionated radiotherapy and with pretreatment and posttreatment contrast-enhanced computed tomography (CT) images were analyzed. Liver segmentations were semiautomatically generated on all CTs and the posttreatment CT was then registered to the pretreatment CT using five commercially available algorithms (Demons, B-splines, salient feature-based, anatomically constrained and finite element-based) in four TPSs. This was followed by an in-depth analysis of 10 DIR strategies (plus global and liver-focused rigid registration) in one of the TPSs. Eight of the strategies were variants of the anatomically constrained DIR while the two were based on a finite element-based biomechanical registration. The anatomically constrained techniques were combinations of: (a) initializations with the two rigid registrations; (b) two similarity metrics - correlation coefficient (CC) and mutual information (MI); and (c) with and without a controlling region of interest (ROI) - the liver. The finite element-based techniques were initialized by the two rigid registrations. The accuracy of each registration was evaluated using target registration error (TRE) based on identified vessel bifurcations. The results were statistically analyzed with a one-way analysis of variance (ANOVA) and pairwise comparison tests. Stratified analysis was conducted on the inter-TPS data (plus the liver-focused rigid registration) using treatment volume changes, slice thickness, time between scans, and abnormal lab values as stratifying factors. Results The complex deformation observed following treatment resulted in average TRE exceeding the image voxel size for all techniques. For the inter-TPS comparison, the Demons algorithm had the lowest TRE, which was significantly superior to all the other algorithms. The respective mean (standard deviation) TRE (in mm) for the Demons, B-splines, salient feature-based, anatomically constrained, and finite element-based algorithms were 4.6 (2.0), 7.4 (2.7), 7.2 (2.6), 6.3 (2.3), and 7.5 (4.0). In the follow-up comparison of the anatomically constrained DIR, the strategy with liver-focused rigid registration initialization, CC as similarity metric and liver as a controlling ROI had the lowest mean TRE - 6.0 (2.0). The maximum TRE for all techniques exceeded 10 mm. Selection of DIR strategy was found to be a statistically significant factor for registration accuracy. Tumor volume change had a significant effect on TRE for finite element-based registration and B-splines DIR. Time between scans had a substantial effect on TRE for all registrations but was only significant for liver-focused rigid, finite element-based and salient feature-based DIRs. Conclusions This study demonstrates the limitations of commercially available DIR techniques in TPSs for alignment of longitudinal images of liver cancer presenting complex anatomical changes including local hypertrophy and fibrosis/necrosis. DIR in this setting should be used with caution and careful evaluation.

We sought to determine whether postoperative chemotherapy after preoperative therapy and pancreatectomy for pancreatic ductal adenocarcinoma (PDAC) prolongs survival.Data to support administering postoperative chemotherapy to patients who received preoperative therapy are lacking.All patients with PDAC who underwent pancreatectomy after preoperative therapy between 2010 and July 2017 at The University of Texas MD Anderson Cancer Center were identified. To control for selection bias, patients who received postoperative therapy and patients who did not were matched by propensity scores based on factors associated with the use of postoperative chemotherapy.Among 245 patients treated with a median of 4 cycles of preoperative treatment and pancreatectomy, 155 (63%) initiated postoperative chemotherapy and 90 (37%) did not. Patients who received postoperative therapy had a higher median cancer antigen 19-9 level before surgery, larger median tumor diameter, higher rate of extrapancreatic invasion, and lower rate of pathologic major response. The propensity-matched cohort comprised 122 patients: 61 who received postoperative chemotherapy and 61 who did not. The median overall survival (OS) and recurrence free survival (RFS) for patients who received postoperative therapy were 42 and 17 months, respectively, versus 32 and 12 months for patients who did not (OS: P = 0.06; RFS: P = 0.04). Postoperative therapy was marginally associated with a longer OS (hazard ratio 0.55, 95% confidence interval 0.29-1.01; P = 0.05) and significantly associated with a longer RFS (hazard ratio 0.55, 95% confidence interval 0.29-0.96; P = 0.04).Despite being administered more frequently to patients with poor prognostic factors, postoperative chemotherapy after preoperative therapy and pancreatectomy for PDAC was of clinical benefit.

Purpose: Pancreatic ductal adenocarcinoma (PDAC) is a heterogeneous disease with variable presentations and natural histories of disease. We hypothesized that different morphologic characteristics of PDAC tumors on diagnostic computed tomography (CT) scans would reflect their underlying biology. Experimental Design: We developed a quantitative method to categorize the PDAC morphology on pretherapy CT scans from multiple datasets of patients with resectable and metastatic disease and correlated these patterns with clinical/pathologic measurements. We modeled macroscopic lesion growth computationally to test the effects of stroma on morphologic patterns, hypothesizing that the balance of proliferation and local migration rates of the cancer cells would determine tumor morphology. Results: In localized and metastatic PDAC, quantifying the change in enhancement on CT scans at the interface between tumor and parenchyma (delta) demonstrated that patients with conspicuous (high-delta) tumors had significantly less stroma, higher likelihood of multiple common pathway mutations, more mesenchymal features, higher likelihood of early distant metastasis, and shorter survival times compared with those with inconspicuous (low-delta) tumors. Pathologic measurements of stromal and mesenchymal features of the tumors supported the mathematical model's underlying theory for PDAC growth. Conclusions: At baseline diagnosis, a visually striking and quantifiable CT imaging feature reflects the molecular and pathological heterogeneity of PDAC, and may be used to stratify patients into distinct subtypes. Moreover, growth patterns of PDAC may be described using physical principles, enabling new insights into diagnosis and treatment of this deadly disease.

Background Significant overtreatment of intraductal papillary mucinous neoplasms can be attributed to low specificity of the current International Consensus Guidelines as well as nonconformity with the guidelines. We compare the ability of the 2012 and revised 2017 intraductal papillary mucinous neoplasms International Consensus Guidelines to predict high-grade dysplasia/invasive cancer and to determine the preoperative variables that predict resection of benign or low-grade dysplasia in tertiary care centers. Methods Clinical, radiographic, and pathologic data for resected intraductal papillary mucinous neoplasms at 3 high-volume National Cancer Institute Cancer Centers were reviewed and the 2012 and 2017 consensus criteria were retrospectively applied. When International Consensus Guidelines were not met, clinical decision analysis was used to determine the primary indication for resection. Logistic regression identified variables associated with pathologic grade. Results Records for a total of 251 patients were reviewed, 129 of whom (52%) had low-grade dysplasia. The revised 2017 International Consensus Guidelines had high sensitivity (98.4%) and negative predicted value (96.1%), and all high-risk stigmata predicted high-grade dysplasia/invasive cancer; however, specificity remained low (14.8%). Nonconformity with International Consensus Guidelines was the most powerful predictor of low-grade dysplasia on final pathologic examination (9.5; 2.12–40.78). Independent predictors of low-grade dysplasia included age younger than 50 (2.46; 1.08–5.62), fine-needle aspiration without epithelial cells (2.6; 1.43–4.72), and normal duct diameter (3.07; 1.99–4.75). Diabetes developed in 30% of patients after resection. Conclusion Management of intraductal papillary mucinous neoplasms remains clinically challenging. Low specificity of the International Consensus Guidelines and nonconformity with the guidelines continue to contribute to unnecessary pancreatic resections. Improved tools for disease classification as well as a better understanding of the natural history, biology, and rates of progression of intraductal papillary mucinous neoplasms are needed to avoid surgical overtreatment of low-grade intraductal papillary mucinous neoplasms.

To develop and validate a radiomics signature that can predict the clinical outcomes for patients with stage I non-small cell lung cancer (NSCLC).We retrospectively analyzed contrast-enhanced computed tomography images of patients from a training cohort (n = 147) treated with surgery and an independent validation cohort (n = 295) treated with stereotactic ablative radiation therapy. Twelve radiomics features with established strategies for filtering and preprocessing were extracted. The random survival forests (RSF) method was used to build models from subsets of the 12 candidate features based on their survival relevance and generate a mortality risk index for each observation in the training set. An optimal model was selected, and its ability to predict clinical outcomes was evaluated in the validation set using predicted mortality risk indexes.The optimal RSF model, consisting of 2 predictive features, kurtosis and the gray level co-occurrence matrix feature homogeneity2, allowed for significant risk stratification (log-rank P.0001) and remained an independent predictor of overall survival after adjusting for age, tumor volume and histologic type, and Karnofsky performance status (hazard ratio [HR] 1.27; P2e-16) in the training set. The resultant mortality risk indexes were significantly associated with overall survival in the validation set (log-rank P = .0173; HR 1.02, P = .0438). They were also significant for distant metastasis (log-rank P.05; HR 1.04, P = .0407) and were borderline significant for regional recurrence on univariate analysis (log-rank P.05; HR 1.04, P = .0617).Our radiomics model accurately predicted several clinical outcomes and allowed pretreatment risk stratification in stage I NSCLC, allowing the choice of treatment to be tailored to each patient's individual risk profile.

Preoperative chemotherapy provides early treatment of micro-metastases and guaranteed delivery of all components of multimodality therapy for localized pancreatic ductal adenocarcinoma (PDAC). For locally advanced (LA) PDAC, induction chemotherapy is the standard of care. This study evaluated the use of gemcitabine and nab-paclitaxel (Gem/nab-P) as first-line therapy for localized PDAC. Clinicopathologic features, treatment, and outcomes were evaluated for 99 patients with localized PDAC. The patients were staged using previously published criteria as follows: potentially resectable (PR), borderline type A (BR-A) (anatomy amenable to vascular resection), BR-B (biology suspicious for metastatic disease including high CA19-9), BR–C (comorbidities requiring medical optimization), and LA. The 99 patients (PR/BR/LA: 45/14/40) were treated with Gem/nab-P. Clinical staging showed that 20 patients had PR or BR-A disease, whereas 39 patients had BR-B or BR-C disease. The BR-B+C cases included one or more of the following: age of 80 years or older (13%), Eastern Cooperative Oncology Group performance status (ECOG PS) of 2 or more (13%), moderate to severe comorbidities (55%), CA19-9 of 1000 or higher (28%), and suspicion for metastases (21%). The majority of the patients received biweekly Gem/nab-P dosing, which was well tolerated. Pancreatectomy was performed for 12 (60%) of 20 patients with PR+BR-A, 2 (5%) of 39 patients with BR-B+C, and 1 (3%) of 40 patients with LA disease. During a median follow-up period of 26 months, the median overall survival (OS) period was 18 months (95% confidence interval [CI], 15.6–20.5 months) for all the patients, 17 months (95% CI, 14.6–19.5 months) for the unresected patients, and not reached for the resected patients (p = 0.028 for resected vs unresected patients). A significant number of patients with radiographically resectable PDAC albeit aggressive biology (BR-B), medically inoperable conditions (BR-C), or both received biweekly first-line Gem/nab-P. The resection rates were lower for the BR-B/BR-C patients than for the PR/BR-A patients (hazard ratio [HR], 0.43; 95% CI, 0.19–1.00; p = 0.05).

Purpose Previous studies have reported that hyperfractionated accelerated reirradiation can be used as part of multimodality treatment of locally recurrent rectal cancer with acceptable toxicity and promising outcomes. The purpose of this study was to evaluate the outcomes and toxicity of hyperfractionated accelerated reirradiation for patients with primary rectal adenocarcinoma and a history of prior pelvic radiation for other primary malignancies. Methods and materials We identified 10 patients with a prior history of pelvic radiation for other primary malignancies who were treated with hyperfractionated accelerated reirradiation for primary rectal adenocarcinoma. Radiation therapy was administered with 1.5 Gy twice daily fractions to a total dose of 39 Gy to 45Gy. Results The median follow-up time was 3.2 years (range, 0.6-9.0 years). Seven of 10 patients received surgery after reirradiation. The 3-year freedom-from-local-progression rate was 62% for all patients and 80% for patients who underwent surgery. The 3-year overall survival rate was 100%, with 3 deaths occurring at 4.7, 6.5, and 9.0 years after reirradiation. One patient had an acute Grade 3 toxicity of diarrhea, and 1 patient experienced a late Grade 3 toxicity of sacral insufficiency fracture. Conclusions Hyperfractionated accelerated reirradiation was well tolerated with promising rates of freedom from local progression and overall survival in patients with primary rectal cancer with a history of prior pelvic radiation therapy. This approach, along with concurrent chemotherapy and surgery, appears to be a viable treatment strategy for this patient population.

Purpose Irradiation may have significant immunomodulatory effects that impact tumor response and could potentiate immunotherapeutic approaches. The purposes of this study were to prospectively investigate circulating lymphoid cell population fractions during hypofractionated proton therapy (HPT) in blood samples of liver cancer patients and to explore their association with survival. Methods and Materials We collected serial blood samples before treatment and at days 8 and 15 of HPT from 43 patients with liver cancer—22 with hepatocellular carcinoma (HCC) and 21 with intrahepatic cholangiocarcinoma (ICC)—enrolled in a phase 2 clinical trial. All patients received 15 fractions of proton therapy to a median dose of 58 Gy (relative biological effectiveness). We used flow cytometry to measure the changes in the fractions of total CD3+, CD4+, and CD8+ T cells; CD4+ CD25+ T cells; CD4+ CD127+ T cells; CD3+ CD8+ CD25+ activated cytotoxic T lymphocytes (CTLs); and CD3– CD56+ natural killer cells. Results With a median follow-up period of 42 months, median overall survival (OS) in the study cohort was 30.6 months for HCC and 14.5 months for ICC patients. Longer OS was significantly correlated with greater CD4+ CD25+ T-cell (P = .003) and CD4+ CD127+ T-cell (P = .01) fractions at baseline only in ICC patients. In HCC patients, the fraction of activated CTLs mid treatment (at day 8) was significantly associated with OS (P = .007). These findings suggest a differential relevance of immunomodulation by HPT in these liver cancers. Conclusions Antitumor immunity may depend on maintenance of a sufficiently high number of activated CTLs during HPT in HCC patients and CD4+ CD25+ T cells and CD4+ CD127+ T cells prior to treatment in ICC patients. These results could guide the design of future studies to determine the optimal treatment schedules when combining irradiation with specific immunotherapy approaches.

Purpose To evaluate the effect of escalated dose radiation therapy (EDR, defined as doses >50.4 Gy in 28 fractions [59.5 Gy BED]) on overall survival (OS), freedom from local progression (FFLP), and freedom from distant progression (FFDP) of patients with unresectable extrahepatic cholangiocarcinoma (EHCC). Methods A consecutive cohort of 80 patients who underwent radiotherapy for unresectable EHCC from 2001 to 2015 was identified. Demographic, tumor, treatment, toxicity, and laboratory variables were collected. The maximal RT doses ranged from 30 to 75 Gy (median 50.4 Gy, at 1.8‐4.5 Gy/fraction). Gross tumor volume (GTV) coverage by maximal dose in EDR group ranged from 38% to 100%. Kaplan–Meier method was used to estimate OS, FFLP, and FFDP. Univariate and multivariate Cox regression models were analyzed. Results After radiotherapy, median OS, FFLP, and FFDP were 18.7, 22.6, and 24.3 months, respectively. There was no significant difference in OS or FFLP between patients who received EDR to portions of the GTV and patients who did not. On multivariate analysis, bigger GTV, age, and ECOG performance status were independently associated with shorter OS. Local progression on chemotherapy prior to RT was independently associated with shorter FFLP. High baseline neutrophil/lymphocyte ratio (>5.3) was independently associated with shorter FFDP. Toxicity grades were similar in EDR and lower doses except lymphopenia which was higher in EDR (P = 0.053). Conclusions EDR to selective portions of the GTV may not benefit patients with unresectable EHCC despite having acceptable toxicity. New methods to improve local control and survival for unresectable EHCC are needed.

Circulating lymphocytes are exquisitely sensitive to radiation exposure, even to low scattered doses which can vary drastically between radiation modalities. We compared the relative risk of radiation-induced lymphopenia between intensity modulated radiation therapy (IMRT) or proton beam therapy (PBT) in esophageal cancer (EC) patients undergoing neoadjuvant chemoradiation therapy (nCRT).EC patients treated with IMRT and PBT were propensity matched based on key clinical variables. Treatment-associated lymphopenia was graded using CTCAE v.4.0. Using matched cohorts, univariate and multivariable multiple logistic regression was used to identify factors associated with increased risk of grade 4 lymphopenia as well as characterize their relative contributions.Among the 480 patients treated with nCRT, 136 IMRT patients were propensity score matched with 136 PBT patients. In the matched groups, a greater proportion of the IMRT patients (55/136, 40.4%) developed grade 4 lymphopenia during nCRT compared with the PBT patients (24/136, 17.6%, P 0.0001). On multivariable analysis, PBT was significantly associated with a reduction in grade 4 lymphopenia risk (odds ratio, 0.29; 95% confidence interval, 0.16-0.52; P 0.0001).PBT is associated with significant risk reduction in grade 4 lymphopenia during nCRT in esophageal cancer.

Purpose: Understanding the mechanism of radioresistance could help develop strategies to improve therapeutic response of patients with PDAC. The SMAD4 gene is frequently mutated in pancreatic cancer. In this study, we investigated the role of SMAD4 deficiency in pancreatic cancer cells' response to radiotherapy. Experimental Design: We downregulated SMAD4 expression with SMAD4 siRNA or SMAD4 shRNA and overexpressed SMAD4 in SMAD4 mutant pancreatic cancer cells followed by clonogenic survival assay to evaluate their effects on cell radioresistance. To study the mechanism of radioresistance, the effects of SMAD4 loss on reactive oxygen species (ROS) and autophagy were determined by flow cytometry and immunoblot analysis, respectively. Furthermore, we measured radioresistance by clonogenic survival assay after treatment with autophagy inhibitor (Chloroquine) and ROS inhibitor (N-acetyl-l-cysteine) in SMAD4-depleted pancreatic cancer cells. Finally, the effects of SMAD4 on radioresistance were also confirmed in an orthotopic tumor model derived from SMAD4-depleted Panc-1 cells. Results: SMAD4-depleted pancreatic cancer cells were more resistant to radiotherapy based on clonogenic survival assay. Overexpression of wild-type SMAD4 in SMAD4-mutant cells rescued their radiosensitivity. Radioresistance mediated by SMAD4 depletion was associated with persistently higher levels of ROS and radiation-induced autophagy. Finally, SMAD4 depletion induced in vivo radioresistance in Panc-1-derived orthotopic tumor model (P = 0.038). More interestingly, we observed that the protein level of SMAD4 is inversely correlated with autophagy in orthotopic tumor tissue samples. Conclusions: Our results demonstrate that defective SMAD4 is responsible for radioresistance in pancreatic cancer through induction of ROS and increased level of radiation-induced autophagy. Clin Cancer Res; 24(13); 3176–85. ©2018 AACR.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers. It has an excessive desmoplastic stroma that can limit the intratumoral delivery of chemotherapy drugs, and protect tumor cells against radiotherapy. Therefore, both stromal and tumor compartments need to be addressed in order to effectively treat PDAC. We hereby co-deliver a sonic hedgehog inhibitor, cyclopamine (CPA), and a cytotoxic chemotherapy drug paclitaxel (PTX) with a polymeric micelle formulation (M-CPA/PTX). CPA can deplete the stroma-producing cancer-associated fibroblasts (CAFs), while PTX can inhibit tumor proliferation. Here we show that in clinically relevant PDAC models, M-CPA effectively modulates stroma by increasing microvessel density, alleviating hypoxia, reducing matrix stiffness while maintaining the tumor-restraining function of extracellular matrix. M-CPA/PTX also significantly extends animal survival by suppressing tumor growth and lowering the percentages of poorly to moderately differentiated tumor phenotypes. Our study suggests that using multifunctional nanoparticles to simultaneously target stromal and tumor compartments is a promising strategy for PDAC therapy.

Background The assessment of pancreatic ductal adenocarcinoma (PDAC) response to therapy remains challenging. The objective of this study was to investigate whether changes in the tumor/parenchyma interface are associated with response. Methods Computed tomography (CT) scans before and after therapy were reviewed in 4 cohorts: cohort 1 (99 patients with stage I/II PDAC who received neoadjuvant chemoradiation and surgery); cohort 2 (86 patients with stage IV PDAC who received chemotherapy), cohort 3 (94 patients with stage I/II PDAC who received protocol-based neoadjuvant gemcitabine chemoradiation), and cohort 4 (47 patients with stage I/II PDAC who received neoadjuvant chemoradiation and were prospectively followed in a registry). The tumor/parenchyma interface was visually classified as either a type I response (the interface remained or became well defined) or a type II response (the interface became poorly defined) after therapy. Consensus (cohorts 1-3) and individual (cohort 4) visual scoring was performed. Changes in enhancement at the interface were quantified using a proprietary platform. Results In cohort 1, type I responders had a greater probability of achieving a complete or near-complete pathologic response (21% vs 0%; P = .01). For cohorts 1, 2, and 3, type I responders had significantly longer disease-free and overall survival, independent of traditional covariates of outcomes and of baseline and normalized cancer antigen 19-9 levels. In cohort 4, 2 senior radiologists achieved a κ value of 0.8, and the interface score was associated with overall survival. The quantitative method revealed high specificity and sensitivity in classifying patients as type I or type II responders (with an area under the receiver operating curve of 0.92 in cohort 1, 0.96 in cohort 2, and 0.89 in cohort 3). Conclusions Changes at the PDAC/parenchyma interface may serve as an early predictor of response to therapy. Cancer 2018;124:1701-9. © 2018 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Rationale: Exosomes are small extracellular vesicles secreted by most cells that are found in blood and other bodily fluids, and which contain cytoplasmic material and membrane factors corresponding to their cell type of origin. Exosome membrane factors and contents have been reported to alter adjacent and distant cell behavior in multiple studies, but the impact of cancer-derived exosomes on chemoresistance is less clear. Methods: Exosomes isolated from three pancreatic cancer (PC) cell lines displaying variable gemcitabine (GEM) resistance (PANC-1, MIA PaCa-2, and BxPC-3) were tested for their capacity to transmit chemoresistance among these cell lines. Comparative proteomics was performed to identify key exosomal proteins that conferred chemoresistance. Cell survival was assessed in GEM responsive PC cell lines treated with recombinant Ephrin type-A receptor 2 (EphA2), a candidate chemoresistance transfer factor, or exosomes from a chemoresistant PC cell line treated with or without EphA2 shRNA. Results: Exosomes from chemoresistant PANC-1 cells increased the GEM resistance of MIA PaCa-2 and BxPC-3 cell cultures. Comparative proteomics determined that PANC-1 exosomes overexpressed Ephrin type-A receptor 2 (EphA2) versus exosomes of less chemoresistant PC cell lines MIA PaCa-2 and BxPC-3. EphA2-knockdown in PANC-1 cells inhibited their ability to transmit exosome-mediated chemoresistance to MIA PaCa-2 and BxPC-3, while treatment of MIA PaCa-2 and BxPC-3 cells with soluble EphA2 did not promote chemoresistance, indicating that membrane carried EphA2 was important for the EphA2 chemoresistance effect. Conclusion: Exosomal EphA2 expression could transmit chemoresistance and may potentially serve as a minimally-invasive predictive biomarker for PC treatment response. Further work should address whether additional exosomal factors regulate resistance to other cancer therapeutic agents for PC or other cancer types.

PURPOSE/OBJECTIVE(S) Intrahepatic cholangiocarcinoma (iCCA) remains a highly lethal disease. Biomarkers are needed to identify pts who may benefit from specific therapeutic strategies. Here, we hypothesized that imaging features derived from pre-therapy CT are associated with histopathological and clinical outcomes. MATERIALS/METHODS Retrospectively, we identified 60 pts with localized iCCA (24 M, 36 F, median age 65 [range 26-84]), who received upfront resection as a discovery cohort (D1) and 87 pts with locally advanced iCCA (49 M, 38 F, median age 64 [range 30-88]) who received chemo and radiation therapy as a validation cohort (D2). Using the pre-therapy CT, we contoured the tumors in the arterial phase and used a voxel-based method to quantify the tumors enhancing volume (normalized to liver parenchyma), and called this quantification: volumetric enhancement (VE). Using the training cohort only, we performed receiver operating characteristic (ROC) analysis to evaluate the classification ability of VE in differentiating long vs short (36 months) overall survival (OS), and to obtain an optimal cut-off for validation in D2. Corresponding slides from resection specimens of 38 pts from D1 were stained with H&E and digitally analyzed to quantify the tumor infiltration percentage. We used Pearson correlation coefficient, likelihood ratio, Kaplan-Meier and Cox-proportional hazard for statistical analyses. RESULTS As a continuous variable, higher VE values were associated with better OS in D1 (RR = 0.97, 95% CI [0.95-0.99], P = 0.0007) and D2 (RR = 0.96, 95% CI [0.95-0.98], P < 0.0001). On multivariate analyses, VE as a continuous variable was an independent prognostic factor for OS accounting for traditional covariates in D1 (RR = 0.97, 95% CI [0.95-0.99], P = 0.002) and D2 (RR = 0.96, 95% CI [0.94-0.98], P < 0.0001). Using D1, VE demonstrated high accuracy in classifying pts with short vs. long term survival (Area under the curve (AUC) = 0.77), with an optimal threshold of 32.2% to dichotomize the VE into low versus high. Kaplan-Meier analysis showed that pts with high VE tumors had better median OS (145 vs 34 months, P = 0.002 and 46 vs 22 months, P < 0.0001), and distant metastasis free survival DMFS (107 vs 11 months, P < 0.0001 and 29 vs 13 months, P < 0.0001) compared to those with low VE tumors in D1 and D2 respectively. Pts with low VE tumors were more likely to have a higher nodal positivity rate compared to those with high VE tumors in D1 (P = 0.002). Tumors with high VE values had higher histopathological tumor infiltration percentage compared to those with lower VE values (⍴ = 0.72, P < 0.0001). CONCLUSION A CT-based measure of volumetric enhancement was associated with clinical and biological differences in resectable and unresectable iCCA, which may help personalize use of chemotherapy, radiation, and surgery in this disease.